1. Field of the Invention
The invention relates to a variably flexible insertion device and to a method for variably flexing an insertion device. The insertion device may be used to insert an instrument, in particular a scope, such as an endoscope or a colonoscope, into a patient.
2. Description of the Related Art
Various insertion devices for scopes are known in the art. For example, U.S. Pat. No. 6,942,613 to Ewers et al. discloses a shape lockable apparatus and method, in which nestable elements of an overtube are linked by elastic tension wires connected to an actuator to selectively stiffen the overtube for advancing an instrument. Similarly, U.S. Pat. No. 5,759,151 to Sturges uses a spine having cylindrical segments interconnected by a flexible cable. The cable is secured to a controller for selectively stiffening and relaxing the spine. The Ewers et al. and Sturges devices are complicated and have only elastic tension wires or a flexible cable to maintain stiffness.
U.S. Pat. Nos. 6,984,203 and 6,800,056 to Tartaglia et al. teach a guide which advances in a distal portion of a steerable endoscope having a segmented body. Related U.S. Pat. Nos. 6,468,203 and 6,610,007 to Belson et al. disclose a steerable endoscope with a body, a steering control for a distal portion of the body which selects a path within the patients body and a motion controller for a proximal end of the body which assumes the selected curve. A fiber optic imaging bundle or a video camera are disposed in the body. The Tartaglia et al. and Belson et al. devices provide no mechanism for variably stiffening the guide.
U.S. Pat. No. 5,337,733 to Bauerfeind et al. relates to a tubular inserting device with variable rigidity, in which a flexible insertion part has outer and inner walls defining an intermediate space therebetween. Application of a vacuum to the intermediate space causes the inner wall to lie against the outer wall to render the insertion part rigid. The Bauerfeind et al. device relies merely upon contact between the outer and inner walls for rigidity, with no additional stiffening aid.
ASGE Abstract 136 submitted in 1983 discloses a soft-plastic, split, stiffening overtube to be placed over a colonoscope at any point during the examination.